Opioid analgesics are widely used in the clinic to treat moderate to severe pain. However, despite their clinical efficacy, opioid analgesics do suffer from some major drawbacks. One major drawback is that prolonged opioid analgesic use can lead to dependence, which gives rise to withdrawal symptoms if the opioid analgesic treatment is stopped abruptly. This opioid dependence can make opioid analgesics very addictive and prone to abuse. In addition, opioid analgesics are also well known for their ability to produce a feeling of euphoria, motivating some to use opioids recreationally.
The prevalence of opioid analgesic abuse is a major problem and the Food and Drug Administration (FDA) in the United States has initiated a program to encourage manufacturers of extended release and transdermal opioid formulations to consider innovative strategies to reduce the risk of abuse, and thereby encourage safe opioid use.
The transdermal delivery of opioid analgesics is a convenient and effective way to deliver opioid analgesics. However, there remains a need for improved approaches for the transdermal delivery of opioid analgesics.
Aspects of the invention were devised with the foregoing in mind.